In galleries of subterranean mines, it often occurs that overhanging loose rocks appear on wall surfaces, for example after the dynamiting of a mine shafts. It is essential to regularly remove these unstable rocks, as a safety precaution against injuries to mine workers.
It is known to use scaling bars for this purpose. Such scaling bars are elongated rigid tools comprising a penetrating pick tip at one end thereof, for insertion between unstable rocks. An elbowed section of the rigid tool forms a lever, for enabling a mine worker to dislodge these rocks with reduced physical effort. More particularly, these scaling tools have a cam element adjacent the pick end, to provide extra leverage. However, these known scaling tools are still relatively inefficient.
Moreover, scaling bars can be made of a hollow aluminum tube having scaling picks inserts. Such scaling bars, having generally eight feet or more in length can easily be bent out of shape, under the influence of bending strains induced in the aluminum tube while in use.